Study of photoinduced properties in doped hematite single crystals via magnetic resonance

In doped hematite single crystals with and without Morin transition experimental studies are made of optical irradiation influence on magnetic resonance. From an analysis of the temperature and angular dependences of the AFMR parameters of different-quality crystals it is found that the low temperature peculiarities can be explained by a two-centre model whereas the high temperature behaviour needs the supposition of a many-centre mechanism of electronic excitation transference. [Russian Text Ignored].